Electron discharge device



Feb. 7, 1933. v, RONCI ELECTRON DISCHARGE DEVICE Filed April 30, .1930

V. L. Have) Vida/6M Patented Feb. 7, 1933 UNITED STATES PATENT OFFICEVICTOR L. RONCI, BROOKLYN, NEW YORK, ASSIGNOR TO BELL TELEPHONELABORA-TORIES, INCORPORATED, OF NEW YORK, N. Y., CORPORATION OF NEW YORKELECTRON DISCHARGE DEVICE Application -'fi1ed April 30,

This invention relates to an electron discharge device and especially tosuch dev ces employed in short wave transmission systems.

An object of the invention is to preventcurrent leakage or arcingdischarge between the control electrodeor grid and the high potentialanode. i I

7 Another object is to fabricate the electrode structure so that thevarious parts may be salvaged when the device is unfit for furtherservice. In accordancewith this invention, the electrode assembly of adischarge device employed for short wave transmission comprises ametallic anode having two centrally disposed upright members, one end ofeach member being rigidly attached to a glass stem and the other endsjoined together by a spacing member which supports an insulating rod. Ahelical wiregrid or control electrode is positioned within the metallicanodeand is supported from the insulating rod by normally rigidsuspension members which also support an insulating bridging member thefilament is attached. Since the helical wire grid expands duringoperation and expansion is liable to distort the grid structure, therigid supports extending from-the insulating rod are provided with bentportions ofreduced cross-section so that they will serve as yieldingmembers when pressure is exerted on them by the expanding grid, tocompensate for the expansion of the grid. This arrangement forms arugged construction of the electrode assembly which substantiallyeliminates failure from mechanical defects, maintains the separateelectrodes in accurate spaced re lation for highly eflicient operation,increases the insulating paths between the high and low potentialelectrodes, simplifies the electrode assembly, and reduces the cost ofproduction. V V

A feature of the invention relates to the fabrication of the electrodesso that if the de vice fails in service a large number of parts may bereclaimed to be used in rebuilding the discharge device. 7 The metallicanode is formed of two similar shaped portions having flanges which fitinto and are secured to- 1930. Serial 1%.44a49s.

nected together at one end by a bridgingmemher which maintains theparallel relation between the fiat surfaces of the anode and which has acollar portion embracing the insulating rod. The bridging member also,has

split extensions which fit over the T-sha-ped members and theseextensions are fastened to the supporting members by welded links orpins. The other ends of, the supporting members slide over tonguedspacers attached to parallel bands clamped to the glass stem and'arerigidly fastened thereto by links. or pins threaded through the spacersand members and welded to the bands. This arrangement facilitates theremoval of defective parts and replacement with perfectparts,

andin the event of the anode bucklingdue'to high temperature, thesupporting structure may be salvaged and used in another assembly. -Theinitial cost of the discharge device will, therefore, be reduced due tothe reclama- 7 'tion value of the defective device. carrying resilientsupporting hooks to whlch These and other features of the inventionwill'be apparent from the following detailed description when consideredin connection with the accompanying drawing.

Fig. 1' is a view in elevation of a discharge device embodying'all thefeatures of this invention with the enclosing vessel broken away to showthe detail structure,

Fig; 2 shows in perspective the various detail parts of the anodestructure and support and their assembly relation, I

Fig. 3 is an enlarged front view of the superstructure shown at the topof Fig. 1 showing the high insulating path between the anode and otherelectrodes and the expansion suspension members supporting the internalelectrodes, i

. Fig. 4. is a side view of the superstructure shown in Fig. 3, Fig; 5is a view in cross section of the superstructure on the line,55 of Fig.3, and

'Fig. 6 shows in perspective an enlarged View of the bridging membershownin Figs. 4and5. or

Referring to the drawing, the electron dis charge device of thisinvention comprises an enclosing vessel 10 of glass having an inwardlyprojecting stem 11 at one end, the inner end of which is pressed aroundthe leading-in wires for the electrodes. An internal glass tube extendsfrom the inner end of the glass stem 11 and projects from the vessel 10at 12. The glass tube 12 serves as a means for evacuating the vessel 10after which it is sealed off. The terminal end of the glass vessel 10 isenclosed in a protective base having a metal collar portion 13 which isattached to the end of the glass vessel 10 for instance, by cement, andan insulating disc portion 14 carrying terminals 15 for providingexternal connections for the electrodes in the vessel. I

The glass stem 11 is surrounded by a clamping assembly from which thevarious electrodes in the device are supported. This clamping assemblyconsists of two parallel split metallic bands 16 and 17 having angularlips 18 through which a clamping screw may be passed to fasten theclamping assembly on the glass stem 11. The clamping bands 16 ant 17 areformed into a unitary structure and equally spaced apart by parallelmetallic ribs, or tongued spacing members, 19 and 20, formed by sheetmaterial and folded as shown in Fig. 2 with an outwardly projectingflanged portion 21 and flat portions 22 which are welded to the bands 16and 17. The flanged portions 21 extend out from the boundary of thebands 16 and 17 and are arranged in a plane through one diameter of the"cylindrical structure formed by the clamping assembly. A pair of uprightsurporting members or standards 23 and 24 are formed of sheet metal andfolded or fluted at their lower ends to provide a central" groove 25, toslide over the flange 21 of the clamping assembly, and flat parallelsurfaces 26, to lie against the flat portions 22 of the spacing members19. It will be seen from Fig. 2 that the flanged portion 21 and theupright support 23, are pierced with holes in the vicinity of theclamping bands and a wire 27 shown in Fig. 1 is threaded through thepierced portions of the spacing member 19 and the uprightsupports 23 and24, to securely fasten the supports to the clamping assembly. The endsof the wire are welded to the bands 16 and 17 on opposite sides of theupright supports 23 and 24.

In a high voltage power amplier used in short wave transmission systemsthe high potential applied to the plate electrode causes excessiveheating and, therefore, it is necessary to construct the plate electrodeof material which will withstand this high degree of heat. Furthermore,the material of thefplate electrode should be relatively thin so that itwill dissipate the heat more readily; In accordance with this inventionthe plate electrode or anode is formed ofthin sheet molybdenum and isformed of two-similar U-shaped sections 28 and 29 having the edges ofeach section bent outwardly to form a flange 30. The two sect-ions arearranged in opposed relation to form a closed flat cylinder with theflanges of opposite sections in face-to-face relation. In order tostrengthen the thin sheet material against buckling under excessive heatconditions a plurality of corrugations 31v are formed at spacedintervals along. th'e"cylindrical boundary of the anode. Due to thesmall thickness of the flanges 30, itis impossible to weld the twosections of the "anode together since the excessive heat'generated inthe welding arc melts the thin metal when a weld is being ma'de. -'Toovercome this difficulty, the upright supports 23 and 24 are providedwith a'grooved'or folded portion 32 in which the flanges -30 ofthesections 28 and 29 may be inserted and held therein by crimping thefolded portion 32 until the Welding operation can be performed. The flatportions 26 of the uprightsupports 23 and 24 adjacent the plate surfaceareprovided with corrugations 33 coinciding with the corrugations 31 onthe anode surface. Due to the contact surface of the anode of thisinvention being increased by the folded portion 32 of the uprightsupports 23 and'24 and the double edge of the flanges '30 withinthegroove of the folded portion, a satisfactory weld can be secured betweenthese'partswhen welding th'e metal of the thin material. This weld maytake place as shown at spaced intervals 34 along the curved edge of theportion 32 of the upright members. The upright'supporting members 23 and24 are provided with T-sh'aped ends 35 preferably formed continuouswiththe anode portion 32 which project above the upper edge of the anode andare arranged in opposed relation across the short diameter thereof. Thisassembly provides a rigid structure for the anode which will-withstandthe high temperatures prevailing 'in'itsuse and the fabrication of theanodeniay be considerably speeded up due to the simplicity of formingthe various parts which enter the anode assembly. Furthermore,theremovable linkage of the anode supports to the clamping assemblyfacilitates removal ofadefective anode and replacement with a perfectanode when such a condition warrants the substitution for the assemblyof the device.

In order to maintain accurate space relation between theparallel wallsof the anode formed by the U-shaped sections 28 and 29, a bridgingmember is attached to the top of the extensions 35 of the uprightsupports. This bridging membercomprises a metallic strip shown in Fig. 6having a central curved portion 36 and downwardly extending slot tedportions 37 and 38'. Atop piece 39 having an outwardly curved portionprovided with a rib or corrugation 40 is welded to the top of thebridging member to form a tubular sleeve. As shown in Fig. 4, thetubular sleeve is located between the extensions of the upright supportsand the downwardly bent slotted portions 37 and 38 fit over the of. Inorder to prevent longitudinal displacement of the quartz rod within thesleeve of the bridging member a bead 43 is formed on the lower surfaceof the rod intermediate its ends and this bead is seated in a pocket oraperture 44 in the sleeve portion36 of the bridging member. The quartzrod insures a high degree of insulation between the high potential whichis applied to the anode and the lowpotentials applied to the otherelectrodes which will be described hereinafter.

The quartz rod is preferably tubular in form in order to seal shortstubs of metal wire 45 and 46 in the ends thereof by fusing the ends ofthe rod around the wires. Attached to the stub wires 45 and 46 areoutwardly curved suspension members or wires 47 and 48 respectivelywhich are attached to supporting wires 49 and 50 extendinglongitudinally of the anode and within the same. These supporting wiresare encircled by a continuous helix 51 having a configuration similar tothe flat cylindrical form of the anode and coaxially spaced with respectthereto. The wires and helix form the grid or control electrode of thedevice. An insulating plate 52 parallel to the insulating quartz rod 42is interposed between the rod and the upper edge of the anode andcentered in space relation between the extensions 35 of the uprightsupports as shown in Fig. 4. This plate is carried by the gridsupporting wires 49 and 50 and is held against downward displacement bycross rods 53 welded to the wires 49 and 50 adjacent the lower surfaceof the plate 52. The plate 52 is provided with apertures equally spacedfrom the center thereof through which hooks 54 extend to support thebight of the filamentary cathode 55. These hooks are resilientlysupported on the plate 52 by coiled springs 56. This assembly insures ahigh degree of insulation between electrodes having a large differenceof potential and the multiple support between the anode and the filamentprevents leakage of the high voltage to the electrodes.

During operation of the device the high temperature causes'expansion ofthe grid and if no means were provided for compensating for thisexpansion, the grid electrode would be distorted and causeirregularities in the characteristic of the device in' operation.Another advantage which is obtained by this invention is the ability ofthe structure to compensate for expansion of the grid electrode and atthe same time maintain the axial relation of the grid andfilament withrespect to the anode. This is accomplished in accordance with thisinvention by flattening the curved portion of the suspension-members47and 48 as shown at57 in Fig. 4 so that this portion of the suspensionmember is weaker that the rest of the suspension member and as the gridexpands with increasing temperature it will exert pressure on thesuspension I members and the flattened portions 57 yield in alongitudinal direction, to compensate for expansion without deflectingthe axial position of the grid with respect to the anode. The flattenedportions of the suspension members return to their normal position asshown in Figs. 1 and 3 when the grid contracts.

The lower ends of the grid areattached to wires 58 and 59 projectingfrom the stem and the wire 58 iscontinued through the stem to serve as aconnector to the terminal 15 on-the base. Two similar wires 60 and 61are-attached to thefilament and extend through the stem lltobe attachedto theterminals 15. The plate leading-in wire 63 islsea-led in the sideof the stem 11 and extends to theterminal15 and a band 64 welded to theupright 23 is clamped around the'leading-in' wire 63 and welded thereto.The clamping assembly band 17 supports a wire 65 to the upper endof'which isattached a dished plate 66 which serves as a pocket'for apellet of magnesium which is vaporized in the final evacuation ofthedevice to fix occludedgases.

While the invention has been described as embodying all thefea-tures ofthis invention in a single tube of a specific structure, it is, ofcourse, understoodthat any ofthe features may be embodied'indevicesdiffering in structure than that here described and, therefore, theinvention isonly to belimited. within the scope of the appended claims.

What is claimed is: I I I 1. In a discharge device, an electrodecomprising similar U-shaped portions having flanged ends arranged inopposed relation with the flangesin'the same plane, and a groovedmemberembracing adjacent flanges of said portionsi v 2. In a dischargedevice, a plate electrode comprising thin sheet metal U-shaped portionshaving angular ends arranged parallel to the axis of said device, and alongitudinal folded metallic member enveloping walls of said angularends and rigidly holding said ends together.

3. In. a discharge device, a plate electrode comprising similarU-shaped'portions having angular ends projecting outside the boundary ofthe U-shaped portions, and a folded T- shaped metallic member engagingsaid angular ends exterior to the boundary formed by the closed wall ofsaid plate electrode; I

4. In a discharge device, an anode compris-.

ing a pair of U-shaped sections of thin sheet molybdenum having outwardbent extensions arranged in face-to-face relation to form a closed flatcylinder, the material of said sections being too thin to be welded, anda supporting member for said anode having a grooved portion engagingsaid extensions so that a weld may be made between the grooved portionand the edges of the extensions.

5. An electron discharge device comprising a vessel having a stem, aband surrounding said stem, an anode, a support extending from saidanode to said band, and means extending transverse to said support andafi'ixed to the surface of said band for removably attaching saidsupport to said band.

6. An electron discharge device comprising a vessel having a stem, aband surrounding said stem, an anode, a support extending from saidanode to said band, and a pin member passing through'said support andsaid band.

7. .An electron discharge device comprising a vessel having a stem, aband having a longitudinal ridge parallel to said stem, an anode, afluted support spacing said anode from said stem and a wire extendingthrough c said fluted support and ridge and attached to said band oneitherside of said support. v

I 8. In an electron discharge device, an anode assembly comprising anembracing member formed of two circular bands, spacing members ofT-shaped cross-section attached to said bands, an anode, upright membersattached to said anode, said upright members having a groove engagingsaid spacing members, and means fastening said upright members to saidspacing members.

9. In an .electron discharge device, an anode assembly comprising anembracing member formed of two flattened circular bands, spacing membersof T-shaped cross-section attached to said bands, an anode of flattenedcylindrical formation, upright members attached to said anode on theflattened sides thereof, said upright 'members having a groove engagingsaid spacing 'members, means fastening said upright members to saidspacing members, and a bridging member joining said upright membersacross the smaller diameter of said anode.

10. An electron discharge device comprising a vessel having a stem, ahollow electrode, parallel supports attached to said stem and electrode,a bent metallic member bridging said supports a-t-the free ends thereofadjacent said hollow electrode, and pinsengaging said supports andbridging member.

11. An electron discharge'device comprising a vessel having a stem,upright members extending from said stem, a'm'etallic'spacing memberjoined to said upright. members having a tubular portion between saidmembers, a grid and filament insulatingly supported from said spacingmember, and an anode attached to said upright members surrounding saidgrid and filament.

12. An electron discharge device comprising a vessel having a stem, aplate electrode having parallel supports, a spacing member having atubular portion between said supports and bent extensions exterior tosaid supports, an insulating support extending through said tubularportion at right angles to. said parallel supports, and an electrodewithin said plate electrode yieldingly supported by said insulatingsupport.

13. An electron discharge device comprising an enclosing vessel, a plateelectrode have ing parallel supports attached to one end of said vessel,a spacing member having a tubular portion between said supports and bentextensions exterior to said supports, an insulating rod extendingthrough said tubular portion at right angles to said parallel supports,and a plurality of inner electrodes surrounded by said plate electrodesuspended from said insulating rod.

1d. .An electron discharge device comprising an enclosing vessel havinga stem, a plate electrode having parallel supports carried by saidstern, a spacing member attached to said supports having a tubularportion between said supports, an insulating rod extending throughsaidtubular portion at right angles to said parallel supports, anelectrode yieldingly supported by said insulating rod within said plateelectrode, and cooperating means on said tubular portion and insulatingrod to'prevent slipping of said insulating rod.

15. An electron discharge device comprising an enclosing vessel having astem, a metallic anode, metallic support members attached to said stemand anode, an insulating member carried by said support members at thefree ends thereof, an electrode within said anode, and a secondinsulating member suspended from said first insulating member, saidsecond insulating member supporting said electrode.

16. An electron discharge device comprising an enclosing vessel having astem, a pair of upright members secured to said stem, an anode supportedby said members, an insulating rod arranged at right angles to the axisof said stem, a collar supported by said members and embracing. said rodintermediate its ends, a grid Within said anode supported by said rod,an insulator extending across one end of said grid and a cathode suported at one end fromsaid insulator and at the other end from saidstem.

17. An electron discharge device compris metallic anode, metallicsupport members attached to said stem and anode, an insulating membercarried by said support members at the free ends thereof, a suspensionmember extendin from each end of said insulating member aving aflattened loop portion, a flat plate carried by said suspension membersand lying parallel to said insulating memher, and a plurality ofelectrodes extending from said plate and enclosed by said anode.

18. An electron discharge device comprising a vessel having a stem, ahollow anode having parallel flat walls supported from said stem,parallel projections on said anode, a metallic sleeve member bridgingsaid projections to maintain the space relation of the walls of saidanode, a cross insulating member held in said metallic sleeve, a secondinsulating member interposed between said cross member and anode, aplurality of electrodes within said anode supported by said secondinsulating member, and a pair of oppositely disposed looped expansionmembers supporting said electrodes and second insulating member fromsaid cross member.

19. An electron discharge device compris ing a vessel having a stem, ahollow anode having parallel fiat walls supported from said stem,parallel projections on said anode, a metallic sleeve member bridgingsaid projections to maintain the space relation of the Walls of saidanode, a cross insulating member held in said metallic sleeve, a secondinsulating member interposed between said cross member and anode, aplurality of electrodes supported by said second insulating memberwithin said anode, and a pair of wire hook members located between saidcross member and second insulating member and having a portion flattenedin the hook area to allow longitudinal expansion only.

20. An electron discharge device comprising anenclosing vessel having astem, a clamping assembly on said stem having a pair of ring membersspaced apart by oppositely disposed connectors of T-shaped crosssection,a pair of metallic uprights having a grooved portion to engage saidconnectors, a hollow two part anode offlattened cylindrical form havingflanged portions held together by other grooved portions of saiduprights, a metallic spacing and supporting member having a tubularportion and downwardly extending portions engaging the free ends of saiduprights, an insulating rod held in the tubular portion of said spacingmember and extending across the hollow portion of said anode, a flatinsulator located between said rod and anode and parallel thereto, apair of longitudinal supporting wires members located between the endsof both insulators to maintain the axial space relation of said filamentand grid with respect to said anode surface and allow expansion of saidgrid in a longitudinal direction only.

In witness whereof, I hereunto subscribe my name this 28th day of April,1930.

l VICTOR L. RONCI.

extending from said fiat insulator and located within said anode, ahelical wire grid carried by said wires and spaced coaxially from theanode surface, a resiliently mounted hook extending through said flatinsulator, a

